Rotary/reciprocatory motion converter

ABSTRACT

A continuous motion converter for converting rotary motion to reciprocatory motion and/or reciprocatory motion to rotary motion. A pair of wheels are positioned in a spaced co-planar relationship to each other and have an endless flexible drive member received over them. A carrier is located about the outer perimeter of the drive member. The drive member supports at one location thereon a slider which extends across the outer width of the drive member. The slider is slidably received on the carrier to extend to each side thereof for movement with the drive member and transverse movement relative to the axis extending between the wheels whereby with movement of the drive member over the wheels the carrier reciprocates between the wheels and the slider reciprocates transversely on the carrier, support means being provided to support the slider within the carrier continuously throughout movement of the carrier.

BACKGROUND OF THE INVENTION

This invention relates to a continuous motion converter for convertingrotary motion to reciprocatory motion and/or reciprocatory motion torotary motion.

Known means for effecting conversion of rotary motion to reciprocatorymotion have utilised an endless flexible drive member such as a chainaround a pair of spaced wheels where the chain supports a carrier whichwill move with the movement of the chain over the wheels. In most casesthe carrier is supported to one side of the chain in order that it doesnot interfere with the support shafts of the wheels. Where the carrieris supported from both sides of the chain provision must be made toprovide support at the side of the wheels to which the shafts aremounted when the position of the carrier fixed to the chain is inalignment with the shafts. This arrangement however, has also been foundto be unsatisfactory since the other side of the carrier is not sosupported and eccentric loadings are induced on the chain carrier andwheel.

SUMMARY OF THE INVENTION

In one form the invention resides in a continuous rotary toreciprocatory or reciprocatory to rotary motion converter comprising apair of wheels in spaced co-planar relationship to each other having anendless flexible drive member received over them, a carrier located toboth sides of the drive member, said drive member supporting at onelocation thereon a slider which extends to each side of the drivemember, said slider being slidably received to the drive member carrierfor transverse movement relative to the axis between said wheels wherebywith movement of the drive member on rotation of said wheels, saidcarrier reciprocates between said wheels and said slider reciprocatestransversely on the carrier, support means being provided to supportslider at both sides of the drive member from the carrier continuouslythroughout the movement of the carrier.

According to a preferred feature of the invention the slider isengagable with the carrier to each side of the drive member through atleast one roller rotatably supported from the slider and received in thecarrier for said transverse movement.

The invention will be more fully understood in the light of thefollowing description of several specific embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a rotary to reciprocatory motionconverter according to the first embodiment;

FIG. 2 is a side elevation of the second embodiment;

FIG. 3 is a cross-section of the second embodiment;

FIG. 4A through 4D are a series of part sectional elevations of thecarrier of the second embodiment illustrating the movement of the sliderblocks;

FIGS. 5 through 8 depict a mounting shaft structure in accordance withthe second embodiment of the invention; wherein like numerals representlike features of the invention:

FIG. 5 is a plan of one form of shaft mounting of the driven wheel ofthe second embodiment;

FIG. 6 is a sectional view along line 6--6 of FIG. 5; and

FIG. 7 is a sectional view along line 7--7 of FIG. 6;

FIG. 8 is a sectional view along line 8--8 of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The first embodiment as shown at FIG. 1 comprises a pair of wheels 11and 12 wherein one wheel 11 is driven from a rotary power source througha drive shaft 13 and the other wheel is freely rotatable on an idlershaft. Both wheels 11 and 12 are substantially co-planar and areinterconnected by an endless flexible drive member 14 which is engagedwith both wheels 11 and 12. The wheels 11 and 12 are associated with ahousing body (not shown in FIG. 1) having a central axis which issubstantially parallel with the perpendicular axis interconnecting theaxes of rotation of the wheels 11 and 12. The housing body slidablysupports a carrier 15 which extends transversely with respect to thecentral axis of the housing body and extends to both sides of theflexible drive member 14 to provide two parallel transversely extendingside portions 15a and 15b. The opposed faces of the side portions 15aand 15b are formed with a transversely extending track 16. In the caseof the embodiment the track takes the form of a slot extending throughthe walls of the side portions 15a and 15b however, if desired the trackmay be formed as a channel in the opposed faces of the side portions.The flexible drive member 14 supports at a point along its length aslider 17 which takes the form of a fixture with a protruding shaftfixed to the drive member and extending equally to each side of thedrive member 14. The shaft supports a pair of rollers one at each end.Each roller is received in the slots 16 in the side portions 15a and 15bof the carrier. The side portion 15a of the carrier which is located tothe side of the wheels 11 and 12 having the support shafts 13 for thewheels is formed with a gap 20 whereby on movement of the carrier 15past the shaft the side portion can pass over the shaft by the gapmoving past the shaft.

With rotation of the drive shaft 13 the driven wheel 11 is caused torotate and the idler wheel 12 is caused to rotate through the presenceof the flexible drive member 14. As a result of the movement of theflexible drive member 14 the slider 17 is carried in the direction ofmovement of the flexible drive member causing the carrier also to bemoved. On the slider reaching one of the wheels it will be caused tomove from one side of the wheel to the other, with continued rotation ofthe wheels and this transverse movement of the slider 17 is accommodatedthrough the engagement of the rollers of the slider in the tracks 16 ineach side portion 15a and 15b of the carrier. On the slider 17 reachingthe other side of the wheel it will be carried in the opposite directionto that previously produced to take the carrier with it.

To prevent disengagement of the slider 17 from the track 16 of the oneside portion 15a a pair of spaced guide members 18 are supportedadjacent to each of the wheels 11 and 12 which serve to fill the gap 20provided in the one side portion 15a when the carrier is at either ofits end positions and provide a continuation of the track 16 in the oneside portion 15a when the carrier 15 reaches its endmost positions andat the point that the slider 17 is located in the opening 20. Inaddition the guide members 18 are slidably supported from the housingbody support (not shown) to be capable of limited axial movement. Abiassing means 21 biasses the guide member 18 to a position slightlyinnermost of the end position of the carrier whereby on engagement bythe carrier it will be carried to the end position. In addition in theevent of there being some movement of the carrier beyond the endposition as a result of inertial forces the guide member 18 is able tomove accordingly with the carrier to ensure the slider is supportedsubstantially equally to both sides of the drive member 14. In thiscase, the inward spring bias temporarily clamps the guides to thecarrier and would accommodate any axial movement of the carrier as aresult of inertial and/or gravitational forces and/or other forces inthe end regions of the travel of the carrier which may cause the carrierto move axially away from the perimeter of the wheel. It should beappreciated that the biassing means 21 may take any desired form.

The second embodiment as shown at FIGS. 2, 3 and 4 comprises a pair ofwheels 111 and 112 whereby one wheel 111 is driven from a rotary powersource through a drive shaft 113 and the other wheel is freely rotatableon an idler shaft. Both wheels 111 and 112 are associated with a housingbody 119 having a central axis which is substantially parallel with theaxis interconnecting the axes of rotation of the wheels 111 and 112. Thehousing body 119 comprises a rectangular channel section havingobliquely inwardly directed flanges 131 at the edges. A cover plate (notshown) may be fixed to its open face if desired. The housing bodysupports a carrier 115 which extends transversely across the support andwhich substantially lies to both sides of the drive member 114 toprovide two parallel transversely extending side portions 115a and 115b.The opposed faces of the side portions 115a and 115b are each formedwith a track 116 which extends along both side portions and which isformed as a channel in the opposed faces of the side portions 115a and115 b. The drive member 114 supports at a point along its length aslider 117 which takes the form of a fixture with a protruding shaftfixed to the flexible drive member and which extends equally over theflexible drive member transverse thereto. The shaft supports a sliderblock 121 at each end. The slider blocks 121 are received in thechannels 116 in the side portions 115a and 115b. The one side portion115a which is located to the side of the wheels 111 and 112 having theshafts fixed thereto is formed with a gap 120 transverse to the axis ofthe track whereby on movement of the carrier 115 past the shafts, theshafts are received in the gap 120. The length of the slider blocks aresuch that on the slider block moving along the track when the portion ofthe drive member 114 engages either of the wheels 111 or 112, and theslider block engages the opening in the one transversely extendingportion the portion of the slider carrying the shaft does not enter theopening until the leading edge of the slider is engaged with theopposite side of the slot as shown at FIGS. 4a, b, c and d. As a resultboth sides of the shaft are constantly supported by the tracks 116 andsubjected to the same forces which counteract any inertial forces and/orgravitational forces and/or other forces exerted thereon. If desiredguide members similar to the guide members 18 of the first embodimentmay be provided at each end position of the carrier to fill the gap 120on the carrier reaching its end position.

With rotation of the drive shaft 113 the wheel 111 is caused to rotateand the idler wheel 112 is caused to rotate through the presence of theflexible drive member 114. As a result of the movement the flexibledrive member 114 the slider 117 is carried in the direction of movementof the drive member causing the carrier also to be moved. On the sliderreaching one of the wheels 111 it will be caused to move from one sideof the wheel to the other side with further rotation of the wheels andthis transverse movement of the slider 117 is accommodated through theengagement of the slider blocks 121 of the slider in the tracks 116 ineach side portion 115a and 115b of the carrier whereby on the sliderreaching the other side of the wheel it will be carried in the oppositedirection to that previously produced to take the carrier with it.

The carrier 115 of the second embodiment is supported to facilitate itsaxial movement in the housing body 119 by a set of rollers. The rollerscomprise a first set of four rollers 122 located on the outer face ofthe carrier adjacent the open face of the housing body. The rollers arepositioned at the corners of the outer face of the carrier and aredirected obliquely from the carrier to be received against the flanges131 provided at the open face of the housing body innerfaces.

The second set of rollers comprise a pair of rollers 123 located to eachside of the carrier and extending from the innermost face. One roller123a is located uppermost on the carrier while the other roller 123b islocated lowermost on the carrier. Both of the rollers substantiallyengage the internal face of the housing body 119.

The housing body may comprise a formed channel section formed from mildsteel sheeting. The rollers 122 and 123 are mounted to be adjustable intheir radial movement to accommodate dimensional tolerances of thehousing. In the event of there being any discontinuities in thedimensions of the housing body such discontinuities are accommodated bythe resilience of the channel section. In addition such resilience canbe used to provide some preloading on the rollers in the carrier toeliminate lateral movement of the carrier in the housing body. Ifdesired the housing body may be formed as a box section.

The mounting for the shafts second embodiment, as set out in FIGS. 2through 4, is shown in FIGS. 5, 6, 7 and 8; wherein like numeralsrepresent like features of the invention. Each shaft 213 is supported inthe housing member 220 by a first internal bearing 224 supported withina bearing housing 225 extending from the rear face and has a pulleywheel 227 fixed to it. The inner end 218 of the shaft 213 has a wheel211 fixed thereto and is supported from the housing member by aninternal bearing 229 located in a bearing housing 231 located at the endof a boss 230 extending from the internal face of the housing member220. The boss comprises a pair of vertically spaced portions 230a and230b which define between themselves a journal space shaped toaccommodate the shaft 213. The transverse dimension of the boss issubstantially equal to the diameter of the shaft resulting in the sidesof the shaft being exposed. The lower portion 230b of the boss is formedas a downwardly extending gusset between the housing member 220 and thesecond bearing 229. The upper portion 230a has a profiled upper portionconforming to the path of the most adjacent portion of the slider block232 as it moves around the boss as shown at FIG. 6 with movement of theshaft supported thereby around the wheel 211.

A suitable application of the invention relates to a pump utilising apiston. An advantage of the embodiment resides in the capacity to supplymotion for long stroke pumps utilising a piston.

It should be appreciated that the scope of the present invention neednot be limited to the particular scope of the embodiment describedabove. In particular the invention need not be limited to a rotary toreciprocatory motion converter but is equally applicable to areciprocatory to rotary motion converter. In addition the engagementbetween the wheels and endless flexible member may take any suitableform and need not be limited to a chain and toothed wheel relationshipdescribed in relation to the embodiment. In addition the housing bodymay take any suitable form to support the carrier in its reciprocationbetween the wheels. In its support by the housing body the carrier canbe slidably supported by any suitable means. Furthermore if desired bothshafts may be driven to provide the reciprocatory movement of thecarrier or may both be driven as a result of reciprocation by thecarrier.

We claim:
 1. A continuous rotary to reciprocatory or reciprocatory torotary motion converter comprising a pair of wheels in spaced co-planarrelationship to each other and having an endless flexible drive memberreceived over them, a carrier located about the outer perimeter of thedrive member, and a primary slot extending transversly across saidcarrier and a secondary slot intersecting said primary slot to clear ashaft of at least one of said wheels when the carrier is in proximity tosaid one of said wheels, and a slider connected to said drive member,said slider extending across the outer width of said drive member andreciprocating within said primary slot from one side thereof to theother side thereof for movement with the drive member and transversemovement relative to an axis extending between the wheels whereby withmovement of the drive member over the wheels, said slider traversingsaid secondary slot as said drive member passes across said one of saidwheels, and support means for supporting the slider within the carrieras said slider traverses said secondary slot.
 2. A motion converter asclaimed in claim 1 wherein the slider is engageable with the carrierthrough at least one roller rotatably supported from the slider andreceived in the carrier for said transverse movement.
 3. A motionconverter as claimed in claim 1 wherein the slider is engagable with thecarrier through at least one slider block slidably supported from thecarrier for said transverse movement.
 4. A motion converter as claimedin claim 3 wherein the wheels are supported from a base by a shaftextending to at least one side of the wheel and the portion of thecarrier located to at least one side of the carrier being formed with agap to enable the carrier to reciprocate past the shaft.
 5. A motionconverter as claimed in claim 4 wherein said support means includes saidslider blocks being of sufficient length that the distance between themounting of the slider to the slider blocks and each ends of the sliderblock is greater that the width of the gap.
 6. A motion converter asclaimed in claim 1 wherein the wheels are supported from a base by ashaft extending to at least one side of the wheel and the portion of thecarrier located to at least one side of the carrier being formed with agap to enable the carrier to reciprocate past the shaft.
 7. A motionconverter as claimed in claim 6 wherein the support means comprises aguide member supported adjacent to each wheel which is receivable insaid gap on said carrier moving past said shaft to its respective endposition said guide member being formed to receive the slider in itspassage across the gap.
 8. A motion converter as claimed in claim 7wherein the guide member is capable of resilient movement with thecarrier in the direction of said axis when engaged with the carrier. 9.A motion converter as claimed in claim 1 wherein the wheels aresupported at spaced locations on an elongate base and said carrier isguided by the base for axial movement thereon.
 10. A motion converter asclaimed in claim 9 wherein the elongate base is formed of a channelshaped section having inwardly directed flanges at the edges.
 11. Amotion converter as claimed in claim 10 wherein the channel shapedsection comprises a formed-sheet metal section.
 12. A motion converteras claimed in claim 10 wherein the channel shaped section comprises anextruded section.
 13. A motion converter as claimed in claim 10, whereinthe carrier is guided by the inner face of the channel shaped section byrollers mounted to the carrier.
 14. A motion converter as claimed inclaim 12 wherein the wheels are adjustable on the carrier to vary thedegree of outward extension from the carrier.
 15. A continuous rotary toreciprocatory motion converter as claimed in claim 1 wherein at leastone wheel is driven to cause reciprocation of the carrier.
 16. Acontinuous rotary to reciprocatory motion converter as claimed in claim1 wherein the carrier is caused to reciprocate to cause motion of thewheels.